In this paper, we provide empirical insights into the relationship between entry, exit, concentration, and market contestability using 1991 and 1996 Taiwan manufacturing census data. The empirical results show that positive net entry will decrease concentration. In addition, entry is motivated by expected profits, market demand growth, market size and the US market growth. The minimum efficient scale to market size, the capital requirement and product differentiation are factors discouraging. Moreover, research and development is a means of entry to markets by new firms. Through the estimation of barriers, we found some industries, which show low entry barriers and high entry, but high levels of concentration. These industries reflect the existence of contestable market.